The scope of the present invention contemplates "objects" in a multi-dimensional space, which are characterized by vectors or parameter samples received by sensors. The invention sorts the images of the objects. The example employed here to illustrate the invention is a tactical, self-protection electronic warfare system for an airborne vehicle such as an aircraft or missile, which must react to many signals from weapon-directing radars, etc., often within a few seconds. The term vehicle as used herein means any movable platform or device including apparatus that is land-based and otherwise.
An integrated electronic countermeasures system on an aircraft ordinarily includes a radar warning system having great bandwidth for receiving and analyzing hostile radar and other signals. Under some conditions the aircraft may be receiving signals from hundreds of active search or acquisition radar beams. The airborne radar warning system attempts to classify the emitters that are transmitting the beams, by analyzing the received signals, and to prioritize the emitters according to the seriousness or urgency of the threat that each may represent. It then responds appropriately, by jamming, launching flares, deploying chaff, and maneuvering defensively.
A radar warning system often has three major sections, namely:
(a) a "receiving system", comprising directional antennas, receivers and encoders, which measure the direction, frequency, time of arrival, and other parameters of received signals,
(b) a signal "preprocessor" that performs pulse sorting, histogramming, and tracking, for organizing the information about the signals in accordance with their parameters and previously received information, and
(c) a data processor ("postprocessor") for central computing, which utilizes the sorted and organized signal information tactically.
As used in the aircraft defense system example, the present invention is a preprocessor as in paragraph (b) above.